1. Field of the Invention
The present invention is directed to novel heterofulvalene geminal dithiolate compounds and their selenium and tellurium analogs derivatives thereof. These compounds are key synthetic intermediates for the preparation of tetrathiafulvalene derivatives and tetraselenafulvalene derivatives which are useful in optical printing of conducting patterns, in electrochromic displays and in high resolution lithography.
2. Prior Art
It is well known that charge transfer salts containing the organic donors tetrathiafulvalene or selenium analogs tetraselenafulvalenes are the most electrically conducting organic solids (see Coleman et al Solid State Commun. 12, 1125 (1973) and U.S. Pat. No. 4,028,346 to Engler et al). U.S. Pat. No. 4,089,857 to Engler et al discloses the synthesis of tetrathiapentalene and tetraselenapentalene compounds which are used as intermediates for the preparation of tetrathiafulvalene and tetraselenafulvalene, respectfully.
As far as we are aware, the heterofulvalene geminal dithiolate compositions of the present invention are novel. Related structures have been described previously. For example, see a review by D. Coucouvanis in Progress in Inorganic Chemistry, Vol. 11, p. 233, 1970 and publications by Jensen and Henriksen, Acta Chem. Scand., 22, 1107 (1968) and 23, 3213, (1970) ibid.
The above cited prior art does not however, disclose the compositions of this invention, their syntheses or their chemical conversion to novel tetraheterofulvalene derivatives.